Traveling With the Propane On

I do turn the water heater off while I travel but leave the reefer on. Been doing it that way since I replaced my rig with an icebox with one with a reefer. Fires can start for many reasons. My daughter was driving her pickup when it lost power. When she pulled over to the side she smelled smoke and had enough time to undo the seat belt, depart the vehicle and watch it go up in flames. Cause was probably a leaking fuel line.